This Week's Math Skills, Focus, and Vocabulary

In this 45-day module, students build on their Grade 3 work with unit fractions as they explore fraction

equivalence and extend this understanding to mixed numbers. This leads to the comparison of fractions and

mixed numbers and the representation of both in a variety of models. Benchmark fractions play an important

part in students’ ability to generalize and reason about relative fraction and mixed number sizes. Students

then have the opportunity to apply what they know to be true for whole number operations to the new

concepts of fraction and mixed number operations.

Terminology

Benchmark (standard or reference point by which something is measured)

Common denominator (when two or more fractions have the same denominator)

Denominator (e.g., the 5 in 3/5 names the fractional unit as fifths)

Fraction greater than 1 (a fraction with a numerator that is greater than the denominator)

Line plot (display of data on a number line, using an x or another mark to show frequency)

Mixed number (number made up of a whole number and a fraction)

Numerator (e.g., the 3 in 3/5 indicates 3 fractional units are selected)

=, <, > (equal to, less than, greater than)

Compose (change a smaller unit for an equivalent of a larger unit, e.g., 2 fourths = 1 half, 10 ones = 1

ten; combining 2 or more numbers, e.g., 1 fourth + 1 fourth = 2 fourths, 2 + 2 + 1 = 5)

Decompose (change a larger unit for an equivalent of a smaller unit, e.g., 1 half = 2 fourths, 1 ten =

10 ones; partition a number into 2 or more parts, e.g., 2 fourths = 1 fourth + 1 fourth, 5 = 2 + 2 + 1)

Equivalent fractions (fractions that name the same size or amount)

Fraction

Fractional unit (e.g., half, third, fourth)

Multiple (product of a given number and any other whole number)

Non-unit fraction (fractions with numerators other than 1)

Unit fraction (fractions with numerator 1)

Unit interval (e.g., the interval from 0 to 1, measured by length)

Whole (e.g., 2 halves, 3 thirds, 4 fourths)